• Journal of odor and indoor environment
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• v.17 no.4
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• pp.337-345
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• 2018

In this study, we measured the concentration of Particulate Matter($PM_{10}$), Formaldehyde(HCHO), and Total Bacteria Count (TBC) at two facilities: day care centers, and postnatal care centers located in the cities of Gyeonggi, Gangwon, Jeolla and Gyeongsang from January 1, 2012 to December 31, 2015. $PM_{10}$ concentration was similar to the day care centers and postnatal care centers. HCHO concentration was the highest in the postnatal care centers. TBC concentration was the highest in the day care centers. Comparing the different cities, $PM_{10}$ concentration was the highest in Gyeonggi, HCHO concentration was the highest in Gyeonggi, and TBC concentration was the highest in Gyeonggi. As a result of HCHO's risk assessment, it was found that adults exceeded the carcinogenicity tolerance of $10^{-6}$ specified by the US EPA. This study is expected to be helpful in preventing damage to health from the contaminated indoor air at sensitive facilities, and can be used as basic data for indoor air quality management.

• Analytical Science and Technology
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• v.19 no.6
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• pp.544-552
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• 2006

Emission tests were carried out to investigate the characteristics of concentration according to flooring sort using small chamber method. The target Volatile Organic Compounds (VOC) included 27 individual compounds of environmental concern, which were determined by adsorption sampling and thermal desorption coupled with GC/MS method and by DNPH cartridge/HPLC method. The emission factor of Total Volatile Organic Compounds (TVOC) and Formaldehyde (HCHO) was detected $0.3mg/m^2{\cdot}h$ and $0.2mg/m^2{\cdot}h$ respectively, and the floorings of 37 (9 PVC Tile, 10 PVC Sheet, 18 Flooring) were satisfied emission standard. TVOC emission factor appeared in order of concentration of PVC Sheet, PVC Tile, and floor flooring, while HCHO was detected very high emission factor (as $0.4mg/m^2{\cdot}h$) at floor flooring above PVC series (as $0.001mg/m^2{\cdot}h$).

• Journal of the Korea Furniture Society
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• v.24 no.1
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• pp.70-78
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• 2013

Indoor air quality control has been strengthened within childcare facilities and welfare communities for the elderly and infirm. I have researched the indoor air quality of kids caf$\acute{e}$s. The quality was determined by the measurement of $CO_2$ and HCHO, and the result was used in understanding of the current status of indoor air quality control. The higher level of $CO_2$ and HCHO were found in the playground area where children use compared to the area for guardians in kids caf$\acute{e}$s. And the more people in the caf$\acute{e}$s, the more $CO_2$ and HCHO were generated. It is judged that kids furniture produce harmful substances for children. Hence, the government regulations for kids caf$\acute{e}$s should be improved by reinforcing the indoor air quality control, considering that the main customers are children not adults.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.7
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• pp.688-693
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• 2005

Nowaday the natural ventilation rate decreases because the apartment housing is being air-tight. Therefore, Indoor Air Quality (IAQ) and indoor environment grow worse. Especially, Formaldehyde (HCHO), Volatile Organic Compounds (VOCs) which is emitted from the building materials and coating material etc. occur Sick House Syndrome that cause negative impact on resident's respiratory system and body. Therefore in construction field, it will be a important issues that development of a ventilation system with high effectiveness which can exhaust the contaminant out of the building quickly. In this research we evaluated 'wall attachable duct-less Heat Recovery Ventilation (HRV) system with air cleaning function'. We executed a synthetic evaluation about indoor air environment under various operating condition installing the system in real scale apartment house that is built in Anyang city. HRV system with air cleaning function showed good performance by removing HCHO, VOCs with less ventilation energy.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.289-294
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• 2006

Interior finishing materials are known as main VOCs and formaldehyde emission sources in residential buildings. The interior finishing materials are usually comprised of several layers with different emission properties, which complicates the emission patterns of the finishing materials. Thus, experiments on composite finishing materials and each of layers are needed to understand the emission characteristics of interior finishing materials. Results indicate that composite finishing materials have the various emission characteristics according to compositions of the materials and kinds of contaminants. Mostly, the emission rates of composite materials are higher than that of the single layer materials. The main reason is assumed to be rapid diffusion of contaminants from the bottom layer material into the top layer material.

• Journal of Korean Society for Atmospheric Environment
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• v.21 no.6
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• pp.593-603
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• 2005

Passive sampler using 4-amino-3-hydrazino-5-mercapto-1, 2, 4-triazole (AHMT) was developed to determine formaldehyde in indoor environment. The chromatography paper cleaned by $3\%$ hydrogen peroxide solution was experimently determined as a optimum absorbtion filter for the collection of formaldehyde. The passive sampler with a broad cross-sectional area and a short diffusion length was quite good in sensitivity. The passive sampler and the active sampling method with an impinger were strongly correlated with a correlation coefficient of 0.9848. The limits of detection and quantification of the passive sampler for the measurement of formaldehyde in the indoor environment were 7.5 and 10.2 ppb, respectively. Temperature ($19\∼28^{circ}C$) and relative humidity ($30\∼90\%$) had slight influence on the sampling rate of the passive sampler. However, the increase of flow velocity on the surface of sampler resulted in the increase of sampling rate.

• Korean Journal of Metals and Materials
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• v.48 no.2
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• pp.169-174
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• 2010

A micro gas sensor for formaldehyde (HCHO) gas was fabricated by using MEMS (Micro Electro Mechanical System) technology and the sol-gel process. The sensing materials of the $SnO_2$-ZnO system were synthesized by the sol-gel method. The crystal structure and thermal analysis of the $SnO_{2}$-ZnO were characterized by XRD and DSC-TGA. The fabricated gas sensors were tested at various gas concentrations (0.5~5.0 ppm) and different operation temperatures ($350{\sim}550^{\circ}C$). The $SnO_2$-10 mol%ZnO sensor showed the highest sensitivity ($R_s=0.24$) for 1.0 ppm-formaldehyde at $500^{\circ}C$ and response time (90% saturation time) was within 20 seconds.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2004.11a
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• pp.319-322
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• 2004

The purpose of this study is to evaluate the reduction effect of bake out on the concentration of indoor air pollutants by measuring the concentration of indoor pollutants(VOCs, HCHO) after the bake out. As a result of the study, bake out was considerably effective in reducing the concentration o( indoor air pollutants, showing relatively high reduction ratio around 40${\sim}$56%. However, continuous attention and control after the bake out is required for the prevention of the rise of the concentration by subsequent emission.

• Korean Chemical Engineering Research
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• v.56 no.4
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• pp.577-584
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• 2018

This study was conducted to investigate the potential of chicken feather (CF), which is a by-product in poultry industry, as a partial substitute of wood fiber in the production of wood-based fiberboard. Keratin-type protein constituted the majority of CF, and its appearance did not differ from that of wood fiber. When the formaldehyde (HCHO) adsorptivities of CF compared by its pretreatment type, feather meal (FM), which was pretreated CF with high temperature and pressure and then grounded, showed the highest HCHO adsorptivity. In addition, there was no difference between the adsorbed HCHO amounts, which was measured by dinitrophenylhydrazine method, of scissors-chopped CF and CF beated with an electrical blender. Mechanical properties and HCHO emission of medium-density fiberboards (MDF), which were fabricated with wood fiber and 5 wt% CF, beated CF or FM based on the oven-dried weight of wood fiber, were not influenced by the pretreatment type of CF. However, when the values compared with those of MDF made with just wood fiber, thickness swelling and HCHO emission of the MDF were improved greatly with the addition of CF, beated CF or FM. Based on the results, it might be possible to produce MDF with improved dimensional stability and low HCHO emission if CF, beated CF or FM is added partially as a substitute of wood fiber in the manufacturing process of MDF produced with the conventional urea-formaldehyde resin of $E_1$ grade. However, the use of CF or FM in the production of MDF has a low economic feasibility at the current situation due to the securing difficulty and high cost of CF. In order to enhance the economic feasibility, it requires to use CF produced at small to medium-sized chicken meat plants. More importantly, it is considered that the technology developed from this research has a great potential to make provision for the prohibition of animal-based feed and to dispose environmentally avian influenza-infected poultry.

• Journal of the Korean GEO-environmental Society
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• v.17 no.10
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• pp.5-11
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• 2016

In this study, the factors affecting commercialization of $Pt/TiO_2$ catalyst, which can oxidize HCHO at room temperature, was investigated. In order to determine the optimum noble metal loading, the catalytic activity was evaluated by varying the Pt loadings; the best catalytic activity was achieved for 1 wt% of Pt. In addition, the catalyst prepared under the reduction condition showed an excellent HCHO oxidation conversion at room temperature. Based on these results, it was confirmed that the activity could be changed by oxidation state of active metal, and in case of Pt, metallic Pt ($Pt^0$) species was more active on HCHO oxidation at room temperature. As a result of evaluating an effect of space velocity to determine the optimum operating condition, it was found that in the lower space velocity, conversion rate of HCHO was increased due to increase of catalyst bed. Catalytic activity was greater in the presence of moisture than in its absence. Through above results, the key factors for commercialization of oxidation catalyst, which was operated at room temperature even without any additional energy source was confirmed.